I’m wondering what other builders are considering for power and why.
I’m considering the 118hp UL350i, single Fcu model. I like UL power because it’s what the prototype is using so there should be good support there.
UL350i can run 87 octane mogas while the 130hp UL350is requires 93 octane fuel. I will do a survey of local gas stations to see if I can find ethanol free 93 octane. I’m currently running 87 octane ethanol free gas in my cub and it’s widely available. There’s no fuel at my home base.
the prototype has the 130 hp ul350is. They are trying to dial in the prop so I would lost some of that experience with the 118hp motor. So the 118 hp motor is a compromise.
I’m planning the UL350is. I like the simplicity and familiarity of the motor over the rotax. I like direct drive and air cooling. It looks and sounds like an airplane engine. Local flights would get 93 and XC flights would get 100LL. I’m still really interested in how the Rotax 915 install goes as well. I could see the Rotax 915 ones being the highest resale value. I’d also be interested in seeing the performance of a Edge Performance 912is. But as an early adopter I think following the prototype is a safe bet and a great engine that gives great performance.
The Edge Performance modified Jab 3300 could be an option as well. With their system upgrades, they are getting ~140+hp out of the 3300. watching that develop as a compare to the UL350is option.
Sammy, around here 93 is very common. Its not as common for 93 to be ethanol free, our ethanol free is usually 89. I have also heard that Herman can reflash a 350iS ECU to run on 91 and I think maybe as low as 89. So, I believe a 350iS is still an option for you. Check with Herman.
Bryan, the edge jabiru is very interesting and I think will be a huge upgrade for that engine to get fuel injection. I don’t want to be on the leading edge of engine development though. The UL has now been around for quite some time in the current configuration. The edge jabiru is a little too young in development for me but I’m watching closely.
The prototype went with two to meet ASTM standards according to Mark. I guess in case they ever wanted to offer factory built aircraft like Vans does with the RV12 it would already be tested in compliance. Most any one I know with a UL has a single ECU. UL will tell you they have never had an ECU fail in flight. Its pretty expensive for that second ECU, so I was also planning a single ECU.
At this time I am considering the Jabiru 3300 but will be visiting Florida in March so will stop by https://wheelsandwings.net/ to take a look at the ULS.
I have owned two Kitfoxs fitted with Rotax 912UL and absolutely hated them. The new 915 is intriguing but at nearly $50k is just not reasonable.
Really both, the Kitfox was the most unstable aircraft I have flown and the ground handling was not much fun. My CFI has over 26,000 hours of tailwheel time, (he is Van’s lead transition trainer)and he hated it as well.
Balancing the carbs is a real pain, if you don’t get them perfect the engine runs awful. the slightest changes in linkage throws them way off. The 912is okay and I flown some RV12s with it, there are starting to be some issues with the charging stator which really involves removing the engine to repair, the five year hose replacement can be expensive and the $40k + price is more than I want to spend.
I commented in another thread that if I were to build a Highwing it would have Corvair power. I’m truly serious about that as I have found my 3.0 to be an excellent engine, the price is right, and it appears from early comments the the HW could use a bit more weight on the nose. The bonus is it sounds like an aircraft engine!
If one were to build the latest and greatest from Sports Performance Aviation they would have a 3.3 stroked Corvair weighing 215 lbs. Dyno test results from SPA show the engine at 2800 rpm is rated for 118 hp, and 125 hp at 3300 rpm.
But the issue is the engine mount. Neither William Wynne (FlyCorvair) or Dan Weseman (SPA) have given any indication of wanting to entertain building an engine mount for the Sonex HW (if I understand correctly it would be the same as the B model). You can read William’s thoughts on this in his reply to the first post (click “more” to see the entire entry):
Here’s a pull quote, “But here is the reality: Neither Myself nor SPA have any interest in making a motor mount for it. The potential return is too little.”
I don’t have the knowledge/skills to build my own mount. That’s not to say that I could not find that bridge and cross it but I’m not a youngster anymore. Having said that … a highwing would be a bit easier to enter/exit as I enjoy these golden years. I don’t have a clue whether the new & improved Sonex Aviation would entertain either offering the mount or at least the plans to construct one.
Does anyone know if the factory prototype with the UL Power engine has the 30A or 50A alternator? With only about 15A extra available for airframe power with the 30A option powering the ECU, ignition and fuel pumps, I’ve always wondered if people option with the 30A alternator and if the airframe power works out. Something to consider.
Thats a good question. I would guess its the 30amp but I dont know for sure and I am not sure its ever been published anywhere. I know they are using a really low draw solid state master relay to keep amps down.
Another chance to pitch my slightly lighter, zero draw mechanical master contactor! Almost 4 years and approaching 500 hours, it’s one of my favorite features.
Edit: I’ll have to dig up the old pictures and repost in the electrical section.
I think no matter how good of a technical fit a corvair would be, I’d have a hard time going that route at this point & it is pretty tidily summed up in that FB post:
The high wing has been in development for years, and when kits are delivered, it will be years before a handful of builders will be ready for a mount.
I’m 63, and after 37 years in the same business …
Based on my (potentially incorrect) understanding, the corvair market is basically William Wynne & Dan Weseman. As William pointed out, it’ll be a few years before builders (myself included) are ready for engines/mount - I’d have a hard time building a new project where engine support comes from 2 people, one of which would be rapidly approaching 70 at the time of first flight.
I’m sure they’re great engines, but long-term support viability is questionable as far as I can tell.
I think you made a excellent point. There is a finite amount of Corvair engines and they are dwindling rapidly. They used to be a popular choice for the sandrail enthusiasts and those guys are moving on to other imports. I have been completing a Thorpe S-18 a buddy purchased and asked me to complete. It came with with a Blanton Conversion Ford V6 the previous builder spent untold dollars on getting mounted. We weighed the engine, redrive, dual ignition modules, and radiator and it was 426 lbs. We trashed it all and put on a 0-320 which are abundantly available.
I am retired, 68, and lucky enough to have a well equipped 2000 square foot shop just steps away from my home. If the kits parts are shipped according to recent information I hope to have my High Wing Project done by this time next year.
One more point, my CFI is Van’s lead transition pilot and does his training at my home airport. Builders from all over the world come to him to checked out in the models they have been building for years sometimes decades. Those builders have spent all their free time constructing a wonderful aircraft and have not been flying or the only few recent hours they do have is in a rental 150 or the like. I have seen older gentlemen in tears after their first instruction flight understanding they may never be able to develop the skills needed to fly the plane they meticulously have completed.
I generally try to stay out of the back and forth over Corvair conversion engines but allow me to briefly clear up some misinformation.
Corvairs are not in short supply as GM (the largest corporation on the planet at that time) built nearly two million Corvairs.
Secondly … no support? Remember you are building an airplane made by one company that was out of business just a few weeks ago.
You pay your money and you take your chances.
Corvairs aren’t for everyone but they are a great option and well supported. Being part of the culture I know there are plenty of suppliers of parts & technical advice far beyond what the general public assumes.
Is anyone considering the Edge Performance line of engines?
All are based on a Rotax with various HP offerings. Thomas Hauklien, the company owner, has owed/flown Sonex airplanes in the past, so he’s familiar with the airframe. The US distributor is STOL Creek Avaition in KS, which is about 120 miles SW of Topeka, KS where the new Sonex Aviation owner lives.
Still not cheap, but HP for HP cheaper than equivalent 915 or 916.
I’m considering the ep912sti engine from edge performance. Its probably the best power to weight ratio engine for the Phoenix but also more complicated with the Turbo and different cooling needs. I would really like to see the factory work out the details on a Rotax 915 install on the next Phoenix they build as that would be very similar to the Edge Performance engine. But when I talked to Mark at AV about it he mentioned that they would almost have to use a 4 blade prop for that engine. Not sure I like that. I wouldn’t mind a 3 blade if that would work. As of now, I think I’m slightly leaning towards the UL350is as it is such a clean install and seems to perform well.
